1. Field of the Invention
The present invention relates to a method and apparatus of detecting an eye from an inputted facial image, and more particularly, to a method and apparatus of detecting an eye using symmetry and moment characteristics of an object, capable of roughly extracting an eye region from an inputted facial image to detect candidate eye regions through a symmetrical component extraction method using contrast information of the extracted image, and fast and reliably judging accuracy of a finally detected candidate eye region using normalized moment line integral obtained from the contrast information of the detected candidate eye regions.
2. Description of the Related Art
Eye detection technology used for security and user recognition roughly includes three processes of face detection, eye region extraction, and eye region verification.
To enhance the performance of eye detection recognition result, most of all, the face detection, which is a first process, should be accurately performed. Particularly, in a face recognition method using an overall characteristic of a face, how accurately detecting a facial region determines the performance of the face recognition. Since a recent method almost accurately detects a facial region, how accurately finding a coordinate of an eye from a facial region to extract elements of a face or obtain an exact facial region emerges an important subject.
Prior art methods of detecting an eye include: a method of creating projection profiles of contrast with respect to an x-axis and a y-axis, respectively, in a region including an extracted eye, finding minimum values on the x-axis and the y-axis to regard a coordinate of a minimum value as a coordinate of an eye; a template matching method using a plurality of detected eye pair candidates; and a method of detecting regions of two eyes using geometrical characteristics of a face.
However, the method of creating the projection profiles to the x and y axes to detect the coordinates of the eye has a problem of being sensitive to the brightness of an image pixel and thus has a problem that it is difficult to find an accurate coordinate of an eye when a head or eyebrows are contained in the extracted region. Also, the template matching method has problems that a standardized eye template may change depending on a database used during a process of obtaining a template and that an eye detection rate is determined depending on a critical value while passing through a binary process.